The present invention is related generally to the field of semiconductor chips and systems that provide temperature control of local area of semiconductor chips during operation.
Advances in integrated circuit technology have led to faster clock frequencies and greater densities of transistors. These advances have resulted in a corresponding increase in the amount of heat generated by the integrated circuits. With large amounts of heat being generated, the problem of efficient heat dissipation has received increased attention.
Low noise is always the design target of almost all electronic circuits, especially for amplifiers. As an example, a low noise amplifier is the first stage of a communication or measurement system. The noise performance of the amplifier thus determines the sensitivity of the whole system. One method of obtaining low noise is the reduction of the semiconductor device temperature because the power density of the thermal noise (which is the most basic noise source) is proportional to the semiconductor device temperature. An integrated circuit is comprised of large numbers of semiconductor devices.
Thermal management today is done by heat sinks, heat spreaders and thermoelectric coolers, all of which cool the environment but not the semiconductor device temperature due to the high thermal resistance material that surrounds a semiconductor device.
It is known to use a thermoelectric cooler to lower the operating temperature of a semiconductor device. A thermoelectric cooler includes a plurality of thermoelectric cooling elements, which are constructed of materials with dissimilar characteristics. The elements are connected electrically in series and thermally in parallel to provide a plurality of thermoelectric couples. Each thermoelectric couple includes one element having a first characteristic and another element having a second characteristic. The thermoelectric couples are connected between two plates which function as a hot side and a cold side of a thermoelectric cooler. The hot side is thermally connected to a heat sink and the cold side is thermally connected to the semiconductor chip.
Thermoelectric cooling is achieved by passing electric current through the thermoelectric cooler. Thermal energy is drawn from the cold side to the hot side at a rate which is proportional to carrier current passing through the circuit and the number of couples. At the hot side, the thermal energy is dissipated by the heat sink. The thermoelectric cooling effect is greatly increased when the dissimilar conducting materials used are semiconducting materials.
The dissimilar semiconducting materials generally used for thermoelectric cooling are N-type material (more electrons than necessary to complete a perfect molecular lattice structure) and P-type material (fewer electrons than necessary to complete a perfect molecular lattice structure, thus providing holes). The extra electrons in the N-type material and the holes in the P-type material are called “carriers” which function to move the thermal energy from the cold side to the hot side.
Mansuria et al. U.S. Pat. No. 5,032,897, the disclosure of which is incorporated by reference herein, discloses a wire bonded integrated circuit chip which is cooled on its backside by a thermoelectric cooler.
Bhatia U.S. Pat. No. 6,094,919, the disclosure of which is incorporated by reference herein, discloses an integrated circuit chip, which is connected to a circuit board with pins, being cooled by a thermoelectric cooler embedded in a lid.
Newman U.S. Pat. No. 6,196,002, the disclosure of which is incorporated by reference herein, discloses an electronic substrate incorporating a thermoelectric cooler. An integrated circuit, which is wire bonded on its front side to the substrate, is contacted on its back side by the thermoelectric cooler.
Tiku et al. U.S. Pat. Nos. 6,596,635 and 6,614,117, the disclosures of which are incorporated by reference herein, disclose a process for forming metal-filled through wafer vias for electrical conductivity and thermal conductivity advantages.
Macris U.S. Pat. No. 6,727,422, the disclosure of which is incorporated by reference herein, discloses a heat sink/heat spreader incorporating a thermoelectric cooler.
Macias U.S. Patent Application Publication 2003/0218865, the disclosure of which is incorporated by reference herein, discloses an integrated circuit chip cooled by a thermoelectric cooler and associated cooling apparatus, including a temperature probe and controller card.
Lai et al. U.S. Patent Application Publication 2004/0017419, the disclosure of which is incorporated by reference herein, discloses a metal-filled through-substrate interconnect for electrical connectivity.
Andry et al. U.S. Patent Application 2007/0048896, the disclosure of which is incorporated by reference herein, discloses metal-filled through wafer vias in a silicon carrier. The through vias are formed for the purpose of electrically connecting a wiring level to a solder bump.